1. Field of the Invention
The present invention relates to an occupant restraint system in which a side airbag is disposed in a folded state along an upper edge of a door opening of a vehicle body, and the airbag is inflatable by a gas, generated by an inflator, when the vehicle is involved in a collision. Upon inflation, the side airbag is deployed into a curtain shape along the inner face of a side of an occupant compartment.
2. Description of the Related Art
A conventional occupant restraint system is known in, for example, Japanese Patent Application Laid-open Nos. 2000-33847 and 11-235965. These Japanese Patent Application Laid-open Nos. 2000-33847 and 11-235965 disclose an arrangement in which a gas generated by an inflator is guided into the interior of an airbag via a gas supply pipe such as a hose, a duct, or a reinforcement liner tube.
In this conventional arrangement, since the gas supply pipe in the vicinity of the gas nozzle is not fixed relative to the airbag, there is a possibility that the gas nozzle might be blocked by a base fabric of the airbag, thereby preventing the gas from issuing smoothly or damaging the base fabric by the heat and pressure of the gas. Fixing the gas supply pipe in the vicinity of the gas nozzle at an appropriate position within the airbag has therefore been considered, but this requires a special fixing member, thereby causing the problems of an increase in the number of parts and an increase in the number of processing steps.
An arrangement is also known in which an impact absorbing member is provided in the vicinity of a roof side rail where a folded airbag is housed, and the impact absorbing member can be made to collapse by an external load so that it can absorb the impact of a secondary collision to an occupant in the case of a light collision where the airbag does not deploy.
When the folded airbag is mounted in the roof side rail after the impact absorbing member has been mounted in the roof side rail or a roof garnish, both an operation to mount the impact absorbing member and an operation to mount the airbag are required, and there are the problems not only of a deterioration in the manufacturing efficiency, but also of the airbag interfering with the impact absorbing member, thereby degrading the manufacturability. Furthermore, since the conventional impact absorbing member does not have flexibility, in order to mount it along a curved roof side rail it is necessary to divide it into a plurality of sections, and this causes the problem of a further deterioration in the manufacturing efficiency.
As shown in FIG. 22, which corresponds to a cross section along line 6—6 of FIG. 1, in a conventional occupant restraint system, when an airbag 103 is not deployed, it is folded in a space between a roof garnish 101 and an inner member 102 forming a vehicle body, the roof garnish 101 being the innermost layer on the occupant compartment side. The airbag 103, together with a cover 104 covering the airbag 103, is secured by a bolt 105 to the inner member 102. Furthermore, provided beneath the airbag 103 is a guide member 106, which is substantially aligned with a parting line L5 that is a border between the roof garnish 101 and a center pillar garnish 107. This guide member 106 is provided so as to guide the direction in which the airbag 103 deploys toward the parting line L5.
That is, when a gas is supplied to the airbag 103 from an inflator (not illustrated), the airbag 103 starts to inflate, ruptures the cover 104, deploys following the shape of the guide member 106, abuts against an extremity 101a of the roof garnish 101 in the vicinity of the parting line L5, and pushes the roof garnish 101 to the inside of the occupant compartment. As a result, an opening is formed between the center pillar garnish 107 and the roof garnish 101, and the airbag 103 deploys through this opening into the occupant compartment.
However, arranging the occupant restraint system in this way might expose the guide member 106 to a force generated accompanying sudden inflation of the airbag 103 and deform the guide member. The guide member 106 might also be deformed when the vehicle itself is deformed by a collision. Deformation of the guide member 106 might cause a large discrepancy between the position of the parting line L5 and the direction in which the airbag 103 inflates, and there is a possibility that the time taken to form an opening by pushing the roof garnish might vary. Such a variation causes an undesirable variation in the deployment characteristics such as the time to completion of deployment of the airbag 103.
In order to suppress such a variation, if the guide member 106 is formed integrally with the inner member 102, and/or if the rigidity of the guide member 106 is increased, the problems of the production process become complicated, and the vehicle weight increases.
The present invention has been achieved in view of the above-mentioned circumstances, and it is a first object of the present invention to fix the relative position of a gas supply pipe, that is inserted within an airbag, without the need for any special fixing member.
A second object of the present invention is to improve the ease of mounting an airbag and an impact absorbing member.
A third object of the present invention is to make consistently stable the deployment characteristics of an airbag by devising the arrangement of the structure of an occupant restraint system.